Evaluating risk of recurrence in patients with meningioma.

OBJECTIVE: Meningioma prognostication and treatment continues to evolve with an increasing understanding of tumor biology. In this study, the authors aimed to test conventional predictors of meningioma recurrence, histopathology variables for which there exists some controversy (brain invasion), as well as a novel molecular-based location paradigm. METHODS: This is a retrospective study of a consecutive series of patients with WHO grade I-III meningioma resected at The University of Texas Southwestern Medical Center between 1994 and 2015. Time to meningioma recurrence (i.e., recurrence-free survival [RFS]) was the primary endpoint measured. Kaplan-Meier curves were constructed and compared using log-rank tests. Cox univariate and multivariate analyses were performed to identify predictors of RFS. RESULTS: A total of 703 consecutive patients with meningioma underwent resection at The University of Texas Southwestern Medical Center between the years 1994 and 2015. A total of 158 patients were excluded for insufficient follow-up (< 3 months). The median age of the cohort was 55 years (range 16-88 years) and 69.5% (n = 379) were female. The median follow-up was 48 months (range 3-289 months). There was not a significantly increased risk of recurrence in patients with evidence of brain invasion, in patients with otherwise WHO grade I meningioma (Cox univariate HR 0.92, 95% CI 0.44-1.91, p = 0.82, power 4.4%). Adjuvant radiosurgery to subtotally resected WHO grade I meningiomas did not prolong the time to recurrence (n = 52, Cox univariate HR 0.21, 95% CI 0.03-1.61, p = 0.13, power 71.6%). Location (midline skull base, lateral skull base, and paravenous) was significantly associated with RFS (p < 0.01, log-rank test). In patients with high-grade meningiomas (WHO grade II or III), location was predictive of RFS (p = 0.03, log-rank test), with paravenous meningiomas exhibiting the highest rates of recurrence. Location was not significant on multivariate analysis. CONCLUSIONS: The data suggest that brain invasion does not increase the risk of recurrence in otherwise WHO grade I meningioma. Adjuvant radiosurgery to subtotally resected WHO grade I meningiomas did not prolong the time to recurrence. Location categorized by distinct molecular signatures did not predict RFS in a multivariate model. Larger studies are needed to confirm these findings.

Hearing Preservation After Intervention in Vestibular Schwannoma.

OBJECTIVE: This study aimed to assess the durability of audiological outcomes after radiation and surgery in the management of vestibular schwannoma. STUDY DESIGN: Retrospective review. SETTING: Tertiary academic center. PATIENTS: Adults with sporadic vestibular schwannoma and serviceable hearing at the time of intervention. INTERVENTIONS: Gamma Knife, middle cranial fossa, or retrosigmoid approaches. MAIN OUTCOME MEASURES: Pure-tone audiometry and speech discrimination scores. RESULTS: Postintervention serviceable hearing (class A/B) was preserved in 70.4% (n = 130; mean follow-up, 3.31 yr; range, 0-15.25 yr). Of the 49 patients treated with radiation, 19 (39.6%) had serviceable hearing at last follow-up, compared with 38 (46.9% of 81) who underwent retrosigmoid (n = 36 [44.4%]) and middle cranial fossa (n = 45 [55.6%]) approaches (odds ratio [OR], 1.40; 95% confidence interval [CI], 0.67-2.82; p = 0.47). A matched analysis by age, tumor volume, and preintervention hearing (n = 38) also found no difference in hearing preservation (HP) likelihood between surgery and radiation (OR, 2.33; 95% CI, 0.24-35.91; p = 0.59). After initial HP, 4 (9.5%) surgical versus 10 (37.0%) radiated patients subsequently lost residual serviceable (A/B) hearing (OR, 0.18; 95% CI, 0.06-0.69; p = 0.01) at a mean 3.74 ± 3.58 and 4.73 ± 3.83 years after surgery and radiation, respectively. Overall, 5- and 10-year HP rates (A/B) after initially successful HP surgery were 84.4 and 63.0%, respectively. However, survival estimates declined to 48.9% at 5 years and 32.7% at 10 years when patients with immediate postoperative serviceable hearing loss were also included, which were comparable to radiation-HP rates at 5 and 10 years of 28.0 and 14.2%, respectively ( p = 0.75). CONCLUSIONS: After vestibular schwannoma intervention, overall HP was similar between radiated and surgical cohorts. However, when successful, surgical approaches offered more durable hearing outcomes at long-term follow-up.

Endoscopic endonasal approach to the craniovertebral junction.

The surgical approach to lesions of the ventral craniovertebral junction (CVJ) has evolved significantly in the last several years with the advent of endoscopic skull base surgery. Differing pathologies of the CVJ can result in irreducible compression of the cervicomedullary region. The endoscopic endonasal approach lends itself well to this region due to the ventral location, and while there is a steep learning curve, is a safe and effective way to perform decompression of the cervicomedullary region. Herein, we discuss the anatomy of the CVJ, preoperative evaluation and surgical considerations, our surgical approach, complications, and outcomes.

Distant Pituitary Adenoma Spread: A Systematic Review and Report of 2 Cases.

BACKGROUND: Distant spread of pituitary adenoma outside the sellar/suprasellar region is classified as pituitary carcinoma. Cerebrospinal fluid (CSF)-born spread of pituitary adenoma can occur after tumor cell spillage into the CSF space after surgery, irradiation, or apoplexy and is not necessarily related to intrinsic tumor biology. OBJECTIVE: To systematically review the literature and describe the clinical characteristics and treatment strategies of patients with pituitary carcinomas. We further present 2 cases from our institution. METHODS: A single-center retrospective review of patients with pituitary adenoma spread to distant intracranial locations between 2000 and 2020 was performed. Electronic databases were searched from their inception to May 25, 2021, and studies describing patients with pituitary spread to distant locations were included. RESULTS: Of 1210 pituitary adenoma cases reviewed, 2 (0.16%) showed tumor spread to distant locations. We found 134 additional cases (from 108 published articles) resulting in a total of 136 cases (61.9% were male). The time to tumor spread ranged between 0 and 516 months (median: 96 months). The follow-up duration ranged between 0 and 240 months (median: 11.5 months). All but 2 patients (98.5%) underwent surgical resection before adenoma spread. The 2 exceptions included a patient with evidence of an apoplectic event on autopsy and another patient with leptomeningeal pituitary spread but an unclear history of apoplexy. Elevated tumor markers were not linked to poor outcomes. CONCLUSION: Distant spread of pituitary adenoma may occur after surgery, irradiation, or apoplexy. It is not necessarily associated with a malignant clinical course.

Surgical Site Infection After Autologous Cranioplasty for Decompressive Craniectomy in Traumatic Brain Injury: A Retrospective Review of Two Level 1 Trauma Centers.

OBJECT: Surgical site infection (SSI) after cranioplasty can result in unnecessary morbidity. This analysis was designed to determine the risk factors of SSI after cranioplasty in patients who received a decompressive craniectomy with the autologous bone for traumatic brain injury (TBI). METHODS: A retrospective review was performed at two level 1 academic trauma centers for adult patients who underwent autologous cranioplasty after prior decompressive craniectomy for TBI. Demographic and procedural variables were collected and analyzed for associations with an increased incidence of surgical site infection with two-sample independent t tests and Mann Whitney U tests, and with a Bonferroni correction applied in cases of multiple comparisons. Statistical significance was reported with a P value of < 0.05. RESULTS: A total of 71 patients were identified. The mean interval from craniectomy to cranioplasty was 99 days (7-283), and 3 patients developed SSIs after cranioplasty (4.2%). Postoperative drain placement (P > 0.08) and administration of intrawound vancomycin powder (P = 0.99) were not predictive of infection risk. However, a trend was observed suggesting that administration of prophylactic preoperative IV vancomycin is associated with a reduced infection rate. CONCLUSIONS: The SSI rate after autologous cranioplasty in TBI patients is lower than previously reported for heterogeneous groups and indications, and the infection risk is comparable to other elective neurosurgical procedures. As such, the authors recommend attempting to preserve native skull and perform autologous cranioplasty in this population whenever possible.

Facial Nerve Outcomes After Vestibular Schwannoma Microsurgical Resection in Neurofibromatosis Type 2.

OBJECTIVE: The aim of this study is to investigate facial nerve outcomes after microsurgical resection in neurofibromatosis type 2 (NF2) compared to sporadic tumors. STUDY DESIGN: Single institutional retrospective chart review. SETTING: Tertiary referral center. METHODS: All adult patients with NF2 vestibular schwannoma (VS) or sporadic VS who underwent microsurgical resection from 2008 to 2019 with preoperative magnetic resonance imaging (MRI) and 1 year of postsurgical follow-up were included. The primary outcome measure was postoperative House-Brackmann (HB) facial nerve score measured at first postoperative visit and after at least 10 months. RESULTS: In total, 161 sporadic VSs and 14 NF2 VSs met inclusion criteria. Both median tumor diameter (NF2, 33.5 mm vs sporadic, 24 mm, P = .0011) and median tumor volume (NF2, 12.4 cm3 vs sporadic, 2.9 cm3, P = .0005) were significantly greater in patients with NF2. The median follow-up was 24.9 months (range, 12-130.1). Median facial nerve function after 1 year for patients with NF2 was HB 3 (range, 1-6) compared to HB 1 (range, 1-6) for sporadic VS (P = .001). With multivariate logistic regression, NF2 tumors (odds ratio [OR] = 13.9, P = .001) and tumor volume ≥3 cm3 (OR = 3.6, P = .025) were significantly associated with HB ≥3 when controlling for age, sex, extent of tumor resection, translabyrinthine approach, and prior radiation. CONCLUSION: Tumor volume >3 cm3 and NF2 tumors are associated with poorer facial nerve outcomes 1 year following microsurgical resection.

The Association of Vestibular Schwannoma Volume With Facial Nerve Outcomes After Surgical Resection.

OBJECTIVE: To explore the relationship between tumor size and facial nerve outcomes following vestibular schwannoma (VS) resection. STUDY DESIGN: Single institutional retrospective chart review of all adult patients with untreated sporadic VS who underwent surgical resection from 2008 to 2018 with preoperative magnetic resonance imaging (MRI) and 1 year of follow-up. The primary outcome measure was facial nerve outcome as assessed by the House-Brackmann facial nerve grading system. RESULTS: One hundred sixty-seven patients, 54.5% female, with a median age of 49 years (20-76 years), were identified who underwent VS resection. Surgical resection was performed by translabyrinthine (76.7%), middle cranial fossa (14.4%), retrosigmoid (7.2%), and transpromontorial (1.8%) approaches. The median tumor diameter and volume were 25.3 mm (range: 4.1-47.1 mm) and 3.17 cm3 (range: 0.01-30.6 cm3 ), respectively. The median follow-up was 24.2 months (range: 12-114.2 months). Gross total resection was performed in 79% of cases, with residual tumor identified on MRI in 17% of cases. For patients with tumors <3 cm3 , 92.7% had grade 1 or 2 facial function after at least 1 year follow-up, compared to 81.2% for those with tumors >3 cm3 (univariate logistic regression OR = 2.9, P = .03). Tumor volume >3 cm3 was predictive of facial weakness on multivariate regression analysis (OR = 7.4, P = .02) when controlling for surgical approach, internal auditory canal extension, anterior extension, age, gender, and extent of resection. CONCLUSIONS: Tumor volume >3 cm3 is associated with worse facial nerve outcomes 12 months following surgical resection. LEVEL OF EVIDENCE: IV Laryngoscope, 131:E1328-E1334, 2021.

Biplane Fluoroscopic-Guided Balloon Rhizotomy for Trigeminal Neuralgia: A Technical Note.

BACKGROUND: The classic percutaneous technique used to cannulate the foramen ovale for the treatment of trigeminal neuralgia can place important anatomic structures, such as the distal cervical internal carotid artery, at risk. OBJECTIVE: To use fixed anatomic landmarks to safely and reliably locate the foramen ovale on anteroposterior (AP) fluoroscopy. METHODS: Locating the foramen ovale was initially tested using AP fluoroscopy on cadaveric skulls in the neurosurgical simulation lab. Fluoroscopic landmarks were identified and utilized to assist in successfully locating the foramen ovale during percutaneous balloon rhizotomy procedures in patients with trigeminal neuralgia. This technique has been successfully used in multiple patients. In this report, we describe our technique in detail. RESULTS: The AP fluoroscopy is directed laterally in the coronal plane until a line drawn inferiorly from the lateral orbital rim bisects the inner concavity of the mandibular angle. Fluoroscopy is then directed inferiorly until the top of the petrous ridge bisects the mandibular ramus. The foramen ovale will come into view within the window between the mandibular ramus and hard palate. Two case illustrations are provided. CONCLUSION: Balloon rhizotomy is a commonly used treatment option for trigeminal neuralgia. Direct visualization of the foramen ovale can reliably be achieved on AP fluoroscopy using specific anatomic landmarks. This technique can be utilized to increase the accuracy and safety of the procedure.

Retrosigmoid Craniectomy for Vestibular Schwannoma with Hearing Preservation.

Objectives To describe a retrosigmoid craniectomy, hearing-preservation approach for resection of vestibular schwannoma. Design/Setting/Participants A video of a single patient undergoing the above approach at a tertiary care skull base surgery program. Results This video demonstrates a retrosigmoid craniectomy approach for resection of an enlarging intracanalicular vestibular schwannoma in a patient with normal hearing. The video highlights the pertinent surgical anatomy and outlines in a step-by-step fashion the surgical steps. The patient obtained a gross total resection with preservation of hearing. Conclusion A retrosigmoid craniectomy approach for vestibular schwannoma offers a potentially hearing preservation approach for selected tumors. The link to the video can be found at: https://youtu.be/VM663XztRZw .

Transcanal Microscopic Transpromontorial Approach for Vestibular Schwannoma.

Objectives This video demonstrates the transcanal transpromontorial approach for resection of vestibular schwannoma. Design/Setting/Participants Present study is based on a video of a single patient undergoing the above approach at a tertiary care skull base surgery program. Results This video demonstrates a transcanal microscopic transpromontorial approach for resection of an enlarging intracanalicular vestibular schwannoma in a young patient with nonserviceable hearing. The video highlights the pertinent surgical anatomy and outlines, in a step-by-step fashion, the approach to the internal auditory canal via this minimally invasive approach. The surgical indications and reconstructive techniques are also discussed ( Fig. 1 ). Conclusions A transcanal microscopic transpromontorial approach for vestibular schwannoma is feasible and offers a minimally invasive option for patients electing for microsurgical resection. The link to the video can be found at: https://youtu.be/-oKkRooytws .

Fractionated CyberKnife Stereotactic Radiotherapy for Perioptic Pituitary Adenomas.

OBJECTIVE: Stereotactic radiosurgery (SRS) is the reference standard for radiotherapy for pituitary adenomas but has been limited to lesions with sufficient distance (i.e., >3 mm) from the optic apparatus. We used marginless, fractionated (i.e., 25-28 fractions) stereotactic radiotherapy and the CyberKnife to treat pituitary adenomas that were not eligible for SRS. We present the clinical outcomes, including local control, endocrine function, and toxicity from modern fractionated radiotherapy. METHODS: A total of 53 patients were treated for pituitary adenomas within 3 mm of the optic apparatus. The primary endpoint was tumor control with the secondary endpoints of vision and pituitary function preservation and endocrine control in hormone-secreting tumors. RESULTS: The tumor control rate as measured on magnetic resonance imaging as either stable or decreased in size was 98.1% (52 of 53) at a mean follow-up of 32.5 months (range, 3-77). All patients experienced preservation or improvement of their preexisting vision status. No change in pituitary function was noted in 52 of the 53 patients (98.1%). One patient experienced worsening of pituitary function secondary to pituitary apoplexy that occurred 4 months after treatment. The endocrine control rate in hormone-secreting tumors was 75% (6 of 8). CONCLUSIONS: Marginless, fractionated CyberKnife radiotherapy demonstrated excellent local tumor control and endocrine control rates, comparable to those with SRS, with preservation of vision in patients with adenomas in close proximity to the optic pathway.

Combined Microsurgical, Endovascular, and Endoscopic Approach to the Treatment of a Giant Vertebrobasilar Aneurysm.

BACKGROUND: Dolichoectasia is defined as elongation and dilatation of a blood vessel. In the intracranial circulation, the basilar artery is affected in 80% of cases. These are challenging lesions with an aggressive natural history, and treatment carries a relatively high rate of morbidity and mortality. We describe a case of multimodal treatment including endovascular, open microsurgical, and endoscopic endonasal approach (EEA) for management. OBJECTIVE: To describe the technical nuance of the addition of the EEA for management of posterior circulation dolichoectasia. METHODS: A 44-yr-old Hispanic woman with a 2-mo history of progressive headaches, gait disturbance, and lower cranial nerve dysfunction presented with acute neurologic decline. MRI demonstrated a dolichoectatic vertebrobasilar system with a giant 4.5-cm fusiform basilar aneurysm. RESULTS: She underwent concomitant endovascular bilateral vertebral artery sacrifice with suction decompression and trapping by clip ligation distal to the lesion. Postoperatively, she developed symptomatic pontine compression. She was then taken for a transclival EEA for intra-aneurysmal thrombectomy. Thereafter, she made a significant functional recovery. CONCLUSION: The addition of endoscopic reconstruction to the treatment of a dolichoectatic basilar aneurysm is an operative nuance that can be employed in treating these highly morbid lesions. This case describing a multimodal treatment paradigm including EEA reconstruction can serve as an example for the future of treatment select cases of dolichoectasia of the vertebrobasilar complex.

Neoadjuvant Stereotactic Radiosurgery Before Surgical Resection of Cerebral Metastases.

OBJECTIVE: Stereotactic radiosurgery (SRS) has redefined the treatment paradigm for cerebral metastases. The benefits of SRS after surgical resection of a metastatic brain tumor have been well-defined. However, it is unclear whether preoperative SRS can improve the outcomes in select patients. The present study examined the safety and efficacy of preoperative neoadjuvant SRS (NaSRS) for the treatment of cerebral metastases. METHODS: We performed a retrospective review of 12 patients treated at The University of Texas Southwestern Medical Center. All patients underwent NaSRS, followed by surgical resection of a cerebral metastasis, from 2011 to 2015. Recurrence and overall survival were characterized using Kaplan-Meier and log-rank analyses. RESULTS: The mean age was 57.5 years (range, 39-69). The median follow-up period was 13 months (range, 1-22.6). The median maximum tumor diameter was 3.66 cm (range, 2.19-4.85). The 6- and 12-month local control rates were 81.8% and 49.1%, respectively. The distant disease control rates were 72.7% and 14.5% at 6 and 12 months, respectively. Overall survival was 83.3% and 74.1% at 6 and 12 months, respectively. Two patients developed leptomeningeal disease at a mean of 11.3 months. A trend toward increased local failure was seen with larger tumor volumes and diameters (P = 0.06). CONCLUSIONS: NaSRS is a promising new approach for the treatment of select cerebral metastases that require surgical intervention. The approach is safe and effective at achieving local control. Further randomized studies with larger patient cohorts are necessary to determine whether the long-term outcomes are improved.

Endoscopic Transcanal Transpromontorial Approach for Vestibular Schwannoma Resection: A Case Series.

OBJECTIVE: To demonstrate successful surgical management of vestibular schwannomas via an exclusively endoscopic transcanal transpromontorial approach (EETTA). PATIENTS: Four patients with vestibular schwannomas. INTERVENTIONS: Surgical excision via EETTA. MAIN OUTCOMES: Technique refinements, tumor access, complete tumor removal, and patient morbidity. RESULTS: Three tumors were Koos grade I and one tumor was Koos grade II. All ears had non-serviceable hearing prior to surgery. The EETTA enabled access to the internal auditory canal and porus acousticus as well as limited access to the cerebellopontine angle. Gross total tumor resection was achieved in all cases. There were no intraoperative or postoperative complications and the mean hospital duration was 2.8 days. After a mean follow-up of 5.0 months, all cases had a good facial nerve outcome. CONCLUSIONS: The EETTA can be successfully used for the management of small vestibular schwannomas in ears without serviceable hearing. Additional studies are needed to fully elucidate the risk-benefit profile of this minimally invasive approach.

Intracranial Hemangiopericytomas: Recurrence, Metastasis, and Radiotherapy.

Background Intracranial hemangiopericytomas (HPCs) are characterized by high recurrence rates and extracranial metastases. Radiotherapy provides an adjunct to surgery, but the timing of therapy and the patients most likely to benefit remain unclear. Methods A retrospective review of 20 patients with HPC treated at the University of Texas Southwestern Medical Center between 1985 and 2014 was conducted. Recurrence and metastasis rates along with overall survival (OS) were characterized based on therapeutic approach and tumor pathology using Kaplan-Meier and Cox regression analyses. Results The mean age was 45.6 years (range: 19-77). Gross total resection (GTR) was achieved in 13 patients, whereas 5 patients underwent subtotal resection. Median follow-up was 91.5 months (range: 8-357). The 5-, 10-, and 15-year recurrence-free survival (RFS) rates were 61, 41, and 20%, respectively. Six patients developed metastases at an average of 113 months (range: 42-231). OS at last follow-up was 80%. Importantly, immediate postoperative adjuvant radiotherapy (IRT) did not influence RFS compared with surgery alone or OS compared with delayed radiotherapy at the time of recurrence. Conclusion HPCs have high recurrence rates necessitating close follow-up. Surgery remains an important first step, but the timing of radiotherapy for optimal control and OS remains uncertain.

Calcified Middle Cranial Fossa Mass.

A 21-year-old male presented for evaluation of transient loss of consciousness and was found to have a hyperdense mass in the left middle fossa. He underwent craniotomy for tumor resection. Intra- and extradural invasion was noted. Gross total resection was achieved. Pathology demonstrated a densely cellular neoplasm with predominately spindle cell morphology in a collagen-containing stroma, areas of vascular proliferation, focal mineralization, and regions of cartilage formation. High mitotic index and regions of necrosis were seen. Based on the final diagnosis of osteosarcoma, the patient was referred for chemotherapy and radiation. Intracranial osteosarcoma is a nonmeningiomatous mesenchymal tumor. Most osteosarcomas are meningeal-based and supratentorial. Presentation depends on tumor location and may include focal neurologic deficits, cranial neuropathy, seizures, or symptoms of increased intracranial pressure. Given the relative rarity of intracranial osteosarcoma, there are no established guidelines for treatment, and therapy is guided by experience with systemic osteosarcoma. Gross total resection is recommended whenever feasible. Both chemotherapy and radiation therapy are used as adjuvant therapy. Regardless of treatment, osteosarcoma remains a highly aggressive malignancy with a poor prognosis. Morbidity and mortality may be the result of local recurrence or development of pulmonary or skeletal metastasis.

Symptomatic Parietal Intradiploic Encephalocele-A Case Report and Literature Review.

Encephalocele is a rare condition that consists of herniation of cerebral matter through openings of dura and skull. A majority of encephaloceles are congenital and manifest in childhood. We present a case of a 45-year-old man presenting with contralateral hemiparesis and found to have an extremely rare phenomenon of a symptomatic posttraumatic parietal intradiploic encephalocele (IE) manifesting 36 years following pediatric traumatic head injury. Computed tomography and magnetic resonance imaging confirmed herniation of brain tissue into the intradiploic space. Surgical treatment with reduction of the encephalocele achieved near resolution of preoperative hemiparesis on follow-up. The pathogenesis and a literature review of IE are discussed.

Unusual skull tumors with psammomatoid bodies: a diagnostic challenge.

AIM: We describe a series of three diagnostically challenging, histologically similar fibro-osseous skull masses. METHODS: The cases were identified in our archives among 50,000 neuropathology specimens. A comprehensive review of the histological, immunohistochemical, ultrastructural, and imaging features as well as the clinical outcome was performed. RESULTS: The routine histology was similar in all 3 cases and showed spindle cell proliferations with frequent calcospheres or psammomatoid bodies. There was no evidence of an underlying subdural component. Immunohistochemistry for the meningioma markers EMA and SSTR2A raised the possibility of intraosseous meningioma, as all 3 lesions were convincingly positive for epithelial membrane antigen (EMA) and 1 lesion was convincingly positive for the somatostatin receptor subtype 2A (SSTR2A); weak, questionable positivity for SSTR2 was present in the remaining 2 cases. In addition, electron microscopy was available in 1 case and showed features consistent with meningioma. CONCLUSIONS: Overall, the findings were most consistent with intraosseous meningioma. Primary intraosseous meningiomas are rare lesions that may present a diagnostic challenge. It is important to consider meningiomas in the differential diagnosis, as extradural meningiomas are associated with an increased risk of recurrence and may occasionally undergo malignant transformation.
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Petroclival Chondrosarcoma: A Multicenter Review of 55 Cases and New Staging System.

OBJECTIVE: To analyze clinical outcomes after treatment of petroclival chondrosarcoma and to propose a novel staging system. STUDY DESIGN: Retrospective case review, 1995 to 2015. SETTING: Multicenter study. PATIENTS: Consecutive patients with histopathologically proven petroclival chondrosarcoma. INTERVENTION(S): Microsurgery, endoscopic endonasal surgery, radiation therapy, observation. MAIN OUTCOME MEASURES: Disease- and treatment-associated morbidity, recurrence, mortality. RESULTS: Fifty-five patients (mean age 42 years; 56% women) presenting with primary or recurrent petroclival chondrosarcoma were analyzed. The mean duration of follow-up was 74 months. Among 47 primary cases, the most common presenting symptoms were headache (55%) and diplopia (49%) and the mean tumor size at diagnosis was 3.3 cm. Subtotal resection was performed in 33 (73%) patients and gross total resection in 12 (27%). Adjuvant postoperative radiation was administered in 30 (64%) cases. Preoperative cranial neuropathy improved in 13 (29%), worsened in 11 (24%), and remained stable in 21 (47%) patients; notably, 11 preoperative sixth nerve palsies resolved after treatment. Nine recurrences occurred at a mean of 42 months. The 1-, 3-, 5- and 10-year recurrence-free survival rate for all 45 patients who underwent primary microsurgery with or without adjuvant radiation therapy was 97%, 89%, 70%, and 56%, respectively. Higher tumor stage, larger categorical size (<4 versus ≥4 cm), lack of adjuvant radiation, and longer duration of follow-up were associated with greater risk of recurrence. The overall mortality rate was 2% for patients presenting with primary disease.Analyzing the cohort of 17 cases with 20 recurrences, 3 received salvage surgery alone, 5 radiation therapy alone, 11 multimodality treatment, and one patient has been observed. Tumor control was ultimately achieved in 15 of 17 patients with recurrent disease. One patient (6%) with grade 3 petroclival chondrosarcoma died as a result of rapidly progressive disease within 6 months of salvage treatment. The overall mortality rate was 6% for patients with recurrent disease. CONCLUSION: Gross total or subtotal resection with adjuvant radiation provides durable tumor control with minimal morbidity in most patients. Surgery may improve preoperative cranial nerve dysfunction, particularly in the case of cranial nerve 6 paralysis.